Abstract: The invention relates to a diagnosis apparatus for detecting a defect of at least one of a plurality of light emitting diodes which are interconnected to form a light emitting diode series connecting a first supply terminal to a second supply terminal. The defect is intended to be detected with little wiring outlay. The invention provides that a resistance element is connected in parallel with each light emitting diode and a measuring device is configured to generate a diagnosis current between the two supply terminals in a luminous pause, during which none of the light emitting diodes emit light, said diagnosis current giving rise, at each resistance element, to a voltage lower than a forward voltage, starting from which the light emitting diode respectively connected in parallel emits light, and to provide a voltage value of a diagnosis voltage dropped between the supply terminals.

Abstract: The invention relates to a diagnosis apparatus for detecting a defect of at least one of a plurality of light emitting diodes which are interconnected to form a light emitting diode series connecting a first supply terminal to a second supply terminal. The defect is intended to be detected with little wiring outlay. The invention provides that a resistance element is connected in parallel with each light emitting diode and a measuring device is configured to generate a diagnosis current between the two supply terminals in a luminous pause, during which none of the light emitting diodes emit light, said diagnosis current giving rise, at each resistance element, to a voltage lower than a forward voltage, starting from which the light emitting diode respectively connected in parallel emits light, and to provide a voltage value of a diagnosis voltage dropped between the supply terminals.